A conventional bicycle cushion device generally includes an outer tube connected to the wheel shaft and an inner tube which is movably inserted in the outer tube and connected to the bicycle frame. A spring is used to absorb the load and the inner tube moves into the outer tube. When the bicycle is ridden on a uneven road, the shock is absorbed by the deformation of the spring so that the rider can control the bicycle comfortably. However, the spring has a fixed physical character which cannot be adjusted according needs. If the spring is too “stiff”, it cannot absorb the shocks. If the spring is too “soft”, the rider is difficult to control the bicycle.
The present invention intends to provide an adjustable cushion device which includes an elastic rubber compressible between an outer tube and an inner tube which is movably connected to the outer tube.